Rotary switch with replaceable contact sets



Feb. 4, 1964 T. s. HARRIS, JR., ETAL 3,120,535

ROTARY SWITCH WITH REPLACEABLE CONTACT SETS 4 BY It 46- ATRNz Feb. 4,1964 T. s. HARRIS, JR., ETAL 3,120,585

ROTARY 'SWITCH WITH REPLACEABLE CONTACT SETS Filed Dec. 9, 1958 2sheets-sheet 2 T1 CIAB- United States Patent C) 3,12ll,585 RTARY SWITCHWHH REPLACEABLE CN'ACT ElS Thomas S. Harris, fr., Stamford, Conn., andRobert E.

Lindemann, Farmingdale, NSY., assignors to The Teleregister Corporation,Stamford, Conn., a corporation of Delaware Filed Dec. 9, M58, Ser. No.779,169

6 Claims. (Cl. Zoll-6) This invention relates to electric circuitswitches and more particularly it relates to switches having a pluralityof stationary contact sets and a rotor contact member.

A principal object of the invention is to provide an improvedconstruction of rotary switch having readily replaceable stationarycontact members, whereby any desired switching combinational arrays canbe expediously obtained with a minimum of wiring changes.

Another object is to provide a rotary switch having a contact rotor anda plurality of stationary but readily replaceable contact memberswhereby a large number of different circuit switching combinations canbe effected without disconnecting any permanent wiring to or from theswitch.

Another object is to provide a novel rotary switch construction whichlends itself readily to ganged assembly, and whereby a very large numberof switching combinations can be effected without changing permanentwiring connections at the switch.

A feature of the invention relates to a rotary switch having a number ofstationary contact strips which are supported and anchored so as to bereadily removable or replaced without making any wiring disconnections,

and without having the said contact members subjected I to externalwiring strain as is the case when the external wiring is soldered orsimilarly permanently attached to the contact strips.

Another feature relates to a novel form of rotary switch of the pushbutton operated kind.

A further feature relates to the novel organization, arrangement andrelative location and interconnection of parts which cooperate toprovide an improved multicontact rotary switch.

Other features and advantages not specifically enumerated will beapparent after a consideration of the following detailed descriptions,the appended claims, and the attached drawing.

In the drawing, which shows by way of example certain preferredembodiments,

FIG. l is a plan View of one preferred switch structure embodying theinvention;

FIG. 2 is an enlarged sectional View of FIG. l taken along the line 2 2thereof and viewed in the direction of the arrows;

FlG. 3 is a section taken along the line 3 3 of FIG. 2 and viewed in thedirection of the arrows;

FIG. 4 is an exploded View showing one manner of assembling andanchoring the replaceable stationary contact strips in the switch;

FlG. 5 is an exploded view of a modification of FIG. 4;

FIG. 6 is an enlarged diagrammatic view explanatory of one form ofswitch for effecting transfer contact combination;

FIG. 7 is a view similar to FIG. 6 of another form showing amake-before-break transfer combination;

FIG. 8 is a schematic diagram of one typical array of rotor contacts andremovable stationary contacts;

FIG. 9 is a schematic diagram similar to FG. 8 showmg a different arrayof rotor contacts and stationary contacts;

FIG. 10 is a plan View of one alternative method or" making the rotorcontacts;

3,l2b,585 Patented Feb. 4, 1964 FIG. 11 s a perspective view of thecontacts of FIG. 10 applied to the rotor;

PEG. 12 is a diagrammatic View explaining certain 1nake-beforebreakoperations of the switch according to the invention.

ln certain fields of use it is necessary sometimes to be able toexpeditiously replace defective or worn contacts, and at the same timeit is also desirable to provide a switch capable of effecting a verylarge number of combinational circuit switchings by means of a switchconstruction which occupies relatively small volumetric space. Forexample, in one field of use it is desirable to have a series ofswitches which can be readily mounted on a control panel or keyboard sothat they can be operated by an attendant merely pushing on an operatingbutton projecting from the panel or keyboard. At the same time it isimportant in such devices to be able to change the switchingcombinations of the switch expeditiously for example by easy addition orremoval of contacts and without soldering and unsoldering operations.

One such switch arrangement embodying the invention is shown in FIG. lwherein the panel or keyboard face is designated l@ and the switchproper is provided with an externally projecting operating button lit.The button Il is connected to a blade l2 which slidably passes through aslot in the panel l@ but is incapable of rotation. Attached to the endof blade l2, is a tubular elongated cup-shaped plunger member i3 whichis provided in the wall thereof with a helical slot E4. The outer faceof member i3 has a pair of inclined locking notches l5, 16 adapted to beengaged by a spring detent 17 to lock the member 13 in either of its twopositions. One of these positions may for example be that shown by thefull lines in FIG. l and the other position is represented by thedot-dash outline. rThe detent l' can be released by any suitable means(not shown) to allow the plunger to be returned to its full lineposition by spring 22. For example, where a series of switches andrespective push buttons are provided, they may be interconnected by thewell known interlocking arrangement whereby when one push button isoperated or depressed it automatically unlatches any other push buttonwhich has been previously depressed.

Telescoped into the end of member 13 is a rotary shaft i8 of suitableelectric insulating or dielectric material such as ceramic, Bakelite, orthe like. The reduced shoulder end 12" of shaft llt; rotates in asuitable bearing in an end plate 2b. Shaft lf; carries a radiallyextending pin 2l. which rides in the slot M. A spring 22 is locatedwithin the member .t3 and abuts against the end of shaft lg, thustending to force the member 13 and the button ll to the left of the fullline position as shown in FIG. l. The switch assembly has an oppositeend plate 23 having an opening through which the blade l2 passes. Theend plates 2li and 23 are joined by a pair of insulator plates or strips24, by means of suitable screws or rivets 2d, 27, 28, 29.

As shown more clearly in FlGS. 2 and 3, the upper insulator plate 2d isprovided with a series of rectangular openings one of which is shown inFIG. 2 and designated by the numeral 3i). Each of these openings has alength L which is approximately the same as the diameter D of theinsulator shaft l. Permanently attached to the insulator plate 24 bymeans of rivets or metal eyelets 3l, 32 are respective contact lugs 33,34. One of these contact lugs is shown in enlarged perspective form inFIG. 4. It comprises, for example, a tongue 35 having an opening 36 toreceive the fastening eyelet 3l. It also has another bent-back tongue37having an opening 33 to receive a wire which may be soldered orotherwise permanently connected to the tongue 37. The forward edge oftongue 3S has a tapered portion 39 which is adapted to fit into a slot4t) in an associated metal contact strip 41. The lower end of the strip41 lits into a corresponding slot or opening 42 in the bottom insulator25. A similar contact strip 43 having a slot similar to 4@ is located inthe opening 30 and is removably supported on a projection 44 on contactlug 34 similarly to the manner in which the contact strip 41 issupported on lug 39. Likewise the lower end of Contact strip 43 ts intoa slot 45 in the bottom insulator 25.

As shown in FIG. 2, the contact members 41 and 43 are located onopposite ends of the diameter of shaft 13, and since the diameter D isapproximately the same Vas the length L of the opening Sil, the contactmembers 41 and 43 bear against the surface of the shaft 18 and are thusslightly bowed outwardly so that the upper end of each contact member isfirmly held against the corresponding contact lug 33, 34, and the lowerend of each contact member is firmly pressed against one end of thecorresponding slot 42, 45. Thus, the contact members are anchored inplace at all times without the necessity of soldering or otherwise beingpermanently connected to their respective Contact lugs 33 and 34.Preferably the contact members 41 and 43 are of spring metal strip stocksuch as Phosphor bronze or the like, although if desired they may bemade out of wire stock, as illustrated in FIG. 5, wherein one of thecontact members is shown as a wire 46, the upper end of which isprovided with a ring or loop section 4'7 adapted to t over theprojection 39 on the above described Contact lug. The lower end of wire46 will, of course, pass through an opening similar to opening 42 ininsulator 25.

The insulator rotor shaft 1d carries a first series of contact members48, 49, 511, etc., arranged in linear spaced array along the length ofthe shaft 18, as indicated in FIGS. 3 and 8. A second and similar seriesof contact members 51, 52, 53, etc., is also provided on the shaft 18.The contact of each pair, for example the pair 43 and 51, is displacedaround the shaft 1S a distance somewhat less than 18() degrees so thatwhen the shaft 18 is turned, for example a quarter turn in a clockwisedirection, the contacts 51, 52, 53, etc., engage the correspondingstationary contacts 41-41rz, 41b-41c, 11d-41e; and when turned a quarterturn in the counterclockwise direction the contacts 48, 49, 50, etc.,engage the corresponding stationary contacts 43- 43a, 43b-43c, 43d-43e,etc. The quarter turn of the rotor shaft in either direction is, ofcourse, controlled by the design of the slot 14 as hereinabovedescribed.

The contacts 4S, 49, etc., can be molded into the body of the insulatorrotor shaft 1S, or they may be in the form of electrolytically depositedplatings, or even in the form of separate metal or alloy contact memberswhich are fastened in any suitable way to the shaft 18. Preferably,although not necessarily, each of the contacts on shaft 1S is longenough in the direction of the shaft length, as to bridge or makecontact with a corresponding pair of stationary contacts as shown inFIGS. 3 and 8. Thus, when the shaft is in one position, such as shownschematically in FIG. 8, contact 41 is connected to contact 41a; contact41b to contact 41C, etc. However, if desired, the contacts 4S, 49, etc.,may be of respectively different lengths as schematically shown in FIG.9. Thus, contacts 4S and 51 may be long enough to bridge a pair ofstationary contacts; contacts 49 and 52 may be long enough to bridgethree associated stationary contacts; and contacts 50 and 53 may be justlong enough to engage a single corresponding stationary contact. It willbe understood that the various stationary contacts can be interconnectedin any desired combinations by suitable straps such as 54, 55 dependingupon the circuit functions to be controlled in the two differentsettings of the switch rotor.

Preferably the contacts 48, 49, etc., are slightly raised above thesurface of the rotor 1S so that a more positive contact pressure may beexerted against the respective stationary contact when rotated intoengagement therewith. If desired, instead of having the stationarycontacts located less than 180 degrees around the shaft 1S they may bedisposed diametrically opposite to each other as shown in FIG. 6, and ifdesired, each of the stationary contacts may be provided with a bump oroffset portion 57 at the contacting region. This bump is useful when thecontacts are to be effected in a makebefore-break sequence. Thus, asshown in FIG. 7, the bump 57 on stationary contact 41 may be staggeredvertically with relation to the bump 57 on the opposite stationarycontact 43, so that as the shaft 18 is rotated, for example in aclockwise direction, the contact 51 engages contact 41 before Contact 43breaks from contact 43.

While in the foregoing the rotor shaft 18 is described as being rotatedor oscillated by a manually operated reciprocable plunger of thepush-button kind, any other well known manner of turning the said shaftmay be employed.

Instead of applying the rotor contacts as platings, they may beprefabricated, for example as shown in FIG. l0, by punching out thecomplementary portion 58 from a thin metal sheet 59, leaving theremaining contact strips, such as 60, 61, 62, joined to the body of thesheet by the readily frangible Webs 63--6'7. Adhesive cement is thenapplied primarily to the contact strip portions Gtl, 61, o2. The entirepiece is then bonded to the rotor 18 at the appropriate location, afterwhich the non-adherent or scrap part of the sheet is peeled off leavingthe contacts 69, 61, 62, rmly attached to the rotor periphery. Ifdesired, any sharp or ragged edges on the adherent contacts can besmoothed out by buing. lf a heat curing rubber cement is used to cementthe contacts to the rotor, the scrap portion of the sheet can be easilypeeled oif without endangering the bond between the Contact stripportions of the rotor. While FIGS. 10 and 11 show certain of the contactstrips as being joined by an integral web portion 68, 69, these may notbe necessary, in which case all the contacts can be in the form ofsimple strips displaced around the rotor in accordance with the desiredmake-before-break or break-before-make combination.

FlG. 12 shows a typical rotor in unwrapped or developed form to explainone particular array of the rotor contacts and stationary contacts. InFIG. 12 the location of the stationary contacts 41, 41a, 41b, 41e and43, 43a, 43b, 43e, constitute with their respective strip contacts 71),'71, 72 one particular sequence of make-beforebreak andbreak-before-make. Thus, assuming the rotor 1S moving in the directionof the arrow, the contacts 43 and 43a make with contact 70 beforecontact 43h breaks with contact '70. On the other hand, contact 43bbreaks with contact 70 before it makes with Contact 71. The actualpoints of contacts are indicated schematically in FIG. 12 by thecrosses. It will be understood, of course, that FIG. 12 shows onerepresentative arrangement of make-before-break contacts, and any otherdesired arrangement of the electrodes can be used.

From the foregoing it will be seen that in addition to other features,the switch has the following advantages:

(1) Both the stationary contacts, as well as the rotor contacts can bereadily removed for cleaning or for replacement without disconnectingany of the connected circuit wiring.

(2) It is possible to multiply switching operations by stacking alongthe length of the rotor, numerous switching combinations of stationarycontacts with the latter relatively closely spaced, for example withspacings D1 as small as 3/s inch as indicated in the enlarged view ofFIG. 3.

(3) The various stationary contacts are independently and removablymounted and iirrnly anchored in place but without being subjected to thestrain of external wiring connections which strain is taken up entirelyby the permanently anchored connection lugs 33, 34, etc.

Various changes and modifications may be made in the disclosedembodiments without departing from the spirit and scope of theinvention.

What is claimed is:

1. A switch for producing predetermined circuit closing and openingfunctions comprising an insulating support having spaced members, atleast one of said members having Contact lugs mounted thereon in spacedrelation, each contact lug having a Wiring projection to which Wiringmay be connected and a contact projection, at least one stationarycontact of exible material extending between said members, means at oneend of the stationary contact and one of the members including thecontact projection of said lug to lock the stationary contact in a xedposition relative to said members and electrically connect it to itscontact lug, the opposite end of said stationery contact bearingdirectly against the other spaced member of the insulating support, arotor, means mounting said rotor to rotate on an axis adjacent to and atone side of said stationary contact and between the spaced members ofsaid support, said rotor having a radial dimension to bear against saidexible stationary contact and ex it outwardly between said spacedmembers, and a contact on said rotor for engaging said stationarycontact whereby the engagement of said rotor with said stationarycontact holds the latter against the spaced members of the support ininterlocked relation with the projection of the Contact lug whilepermitting removal thereof by ilexing it to disengage its end from theprojection and withdrawing it from between the members withoutdisassembling any remaining part of the switch or Wiring thereto.

2. A switch for producing predetermined circuit closing and openingfunctions comprising a pair of spaced insulating members having alignedopenings therein, end members connected to said insulating members tomaintain them in spaced parallel relation to form a supporting frame, atleast one of said insulating members having contact lugs mounted thereonin spaced relation, each contact lug having a wiring projection to whicha wire may be connected and a tapered contact tongue projecting into theopening, a liexible spring contact for each contact lug, each springcontact being of a length to extend between the pair of spacedinsulating members and having a slot adjacent one end for interlockingengagement with the Contact tongue of a lug, the opposite end of saidcontact bearing directly against the other insulating member of thepair, a rotor mounted to rotate in the end members of said frame andsaid rotor having a surface projecting radially to bear against eachspring contact tangentially to press it toward the insulating membersand lock it in position on the projecting tongue, and a contact on therotor for selectivity engaging at least one ofthe spring contacts.

3. A switch in accordance with claim 2 in which one of said insulatingmembers has contact lugs mounted thereon on opposite sides ofthe openingtherein, the spring contacts extending between the pair of spacedinsulating members on opposite sides of the opening and engagingopposite sides of the rotor.

4. A switch in accordance with claim 2 in which the spring contact hasan inwardly projecting detent engaging the rotor. 1

5. A switch in accordance with claim 2 in which the spring contact is inthe form of a wire having a loop at one end for an interlockingelectrical engagement with the tongue on its lug.

6. A switch for producing predetermined circuit closing and openingfunctions comprising a pair of spaced insulating members having alignedopenings therein, end members connected to said insulating members tomaintain them in spaced parallel relation to form a supporting frame, atleast one of said insulating members having contact lugs mounted thereonin spaced relation, each contact lug having a wiring projection to whicha wire may be connected and a tapered contact tongue projecting into theopening, a spring contact for each contact lug, each spring contactbeing of a length to extend between the pair of spaced insulatingmembers and having a slot adjacent one end for interlocking engagementwith the contact tongue of a lug, a rotor mounted to rotate in the endmembers of said frame and engaging each spring contact tangentially topress it toward the insulating members and lock it in position on theprojecting tongue, a Contact on the rotor for selectively engaging atleast one of the spring contacts, said rotor comprising axially movableparts, and said axially movable parts having an interengaging pin andhelical slot connection whereby axial movement of one part producesrotation of the part having the contact thereon.

References Cited in the tile of this patent UNITED STATES PATENTS506,841 Bulen Oct. 17, 1893 1,302,035 Hall Apr. 29, 1919 1,673,607Tulloch .Tune 12, 1928 2,186,818 Brown Ian. 9, 1940 2,201,882 Bryant etal May 21, 1940 2,669,611 Siluius Feb. 16, 1954 2,856,674 Hill Oct. 21,1958 2,861,324 Klumpp Nov. 25, s 2,881,272 Parker Apr. 7, 1959 2,912,528Wall Nov. 10, 1959

1. A SWITCH FOR PRODUCING PREDETERMINED CIRCUIT CLOSING AND OPENINGFUNCTIONS COMPRISING AN INSULATING SUPPORT HAVING SPACED MEMBERS, ATLEAST ONE OF SAID MEMBERS HAVING CONTACT LUGS MOUNTED THEREON IN SPACEDRELATION, EACH CONTACT LUG HAVING A WIRING PROJECTION TO WHICH WIRINGMAY BE CONNECTED AND A CONTACT PROJECTION, AT LEAST ONE STATIONARYCONTACT OF FLEXIBLE MATERIAL EXTENDING BETWEEN SAID MEMBERS, MEANS ATONE END OF THE STATIONARY CONTACT AND ONE OF THE MEMBERS INCLUDING THECONTACT PROJECTION OF SAID LUG TO LOCK THE STATIONARY CONTACT IN A FIXEDPOSITION RELATIVE TO SAID MEMBERS AND ELECTRICALLY CONNECT IT TO ITSCONTACT LUG, THE OPPOSITE END OF SID STATIONARY CONTACT BEARING DIRECTLYAGAINST THE OTHER SPACED MEMBER OF THE INSULATING SUPPORT, A ROTOR,MEANS MOUNTING SAID ROTOR TO ROTATE ON AN AXIS ADJACENT TO AND AT ONESIDE OF SAID STATIONARY CONTACT AND BETWEEN THE SPACED MEMBERS OF SAIDSUPPORT, SAID ROTOR HAVING A RADIAL DIMENSION TO BEAR AGAINST SAIDFLEXIBLE STATIONARY CONTACT AND FLEX IT OUTWARDLY BETWEEN SAID SPACEDMEMBERS, AND A CONTACT ON SAID ROTOR FOR ENGAGING SAID STATIONARYCONTACT WHEREBY THE ENGAGEMENT OF SAID ROTOR WITH SAID STATIONARYCONTACT HOLDS THE LATTER AGAINST THE SPACED MEMBERS OF THE SUPPORT ININTERLOCKED RELATION WITH THE PROJECTION OF THE CONTACT LUG WHILEPERMITTING REMOVAL THEREOF BY FLEXING IT TO DISENGAGE ITS END FROM THEPROJECTION AND WITHDRAWING IT FROM BETWEEN THE MEMBERS WITHOUTDISASSEMBLING ANY REMAINING PART OF THE SWITCH OR WIRING THERETO.